Edwin f



(No Model.)

B. FQWARD. POWDER SEPARATOR.

No. 409,258. Patented Aug. 20, 1889.

UNITED STATES PATENT OEFIGE.

EDWIN F. WARD, OF NEW YORK, N. Y.

POWDER-SEPARATO R.

SPECIFICATION forming part of Letters Patent No. 409,258, dated August20, 1889.

Application filed October 24, 1887. Renewed February 25, 1889. SerialNo. 301,164. (No model.)

To all whom it may concern.-

Be it known that I, EDWIN F. WARD, a citizen of the United States,residing at New York, in the county of New York and State of New York,have invented certain new and useful Improvements in Powder-Separators;and I do declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, and to the letters and figures ofreference marked thereon, which form a part of this specification.

My invention relates to apparatus for separating or sifting the coarsefrom the fine particles of any finely-ground material, such as pigments,cements, &c. This is accomplished by means which will be hereinaftermore fully set forth in the specification, and illustrated in theaccompanying drawings, in which Figure 1 is an elevation, partly insection, of the apparatus; Fig. 2, a cross-section of the funnelattached to the air-shaft; Fig. 3, a side elevation of the air-shaft andfunnel, and Fig. 4 a modified form of the bottom of the air-shaft.

It is well known that the presence of coarse material or grit inpigments or cements is objectionable. In the case of metallic pigmentsthe presence of coarse material prevents a smooth surface when mixedwith oil and applied as a paint and causes rough points to appear uponthe applied surface. In the case of cement-such as hydraulic cementthecoarse material is inert and prevents intimate mixture of the finerparticles, and therefore a decrease in breaking and crushing strains.

Ground pigments have been separated by sieves and by floating in water,and cements have been separated by sieves. These methods are found to beunreliable and expensive.

By my device I do away with all sieves and floating and use a column ofair to separate the coarse and fine particles, and at the same timecarry off the fine material.

Referring more particularly to the draw ings, I have shown a pulverizerO of any suitable construction and capacity. One which generates acolumn of air by the rapid revolutions of the crushing-surface may beused,

or a column of air may be forced through the pulverizer. At the top ofthe pulverizer is placed a vertical cylinder or shaft A of a length anddiameter according to the requirements of the material to be ground andseparated. This shaft is extended upward and terminates in a bin orhopper B, forming a dust-chamber, where the fine material is collected.At either side of the hopper I place dust-collectors F of well-knownconstruction. Instead of a hopper, the stack may terminate in a room andscrew conveyers be used for carrying off the fine material as itsettles. Near the bottom E of the shaft A, and at a point above theexit-shaft of pulve-rizer C, I introduce side currents of air by meansof the pipes or hose (Z, leading from the fanblowers D.

If a battery or pulverizers be used, they may have branch bottomshafts-such as (Zleading to the central shaft, and the columns of air bebrought in above the junction and the relations remain the same as inthe single pulverizer.

Around the shaft A, and extending up to the top thereof, is aguard-funnel A, which serves to catch any material which, although quitelight, is not sufiiciently fine for the purpose required. This funnel isbrought to one side of the stack A and terminates in an opening, whichmay have a receptacle for the material, or have an automatic gate. Suchmaterial may thus be removed and carried to the pulverizer forregrinding.

The operation of the device is as follows: The material as it is groundby the pulverizer is carried out and upward by the central or pulverizerair-column into the lower part E of shaft A. It is there met by theair-columns of tubes (Z. The coarse and fine particles are carried uptogether; but as they pass upward the tendency of the heavy particles isto fall back and they are forced out-ward toward the sides of the shaft,and finally fall to the pulverizer, where they are reground. Thefinerparticles are carried up to the top of the shaft, and being drivenout therefrom fall into the bin. The force of the air-currents may beregulated by the speed of the blower or by siich inlets for air placedat any convenient point upon the shaft or cylinder A as may be foundnecessary. The velocity of the upward current through the shaft may beunequal in different portions of its diameter the stronger currentcarrying up fine and coarse together, the coarser and heavier particlesfalling downward through the weaker current toward the pulverizer orreceptacle for tailings, as the case may be. If the heavier particlesare composed of many small ones massed together, they will be separatedfrom each other by falling against the upward current and ultimately becarried to the dustehamber. The advantages of this method of separatingare that with great rapidity and by one operation it separates from thecoarse the suflieiently fine particles, thus increasing the property ofthe fine product and consequently the value of the total product, whileat the same time the rapidity of the process and the avoidance of muchhandling both increase the amount and diminishes the cost of such totalproduct.

To further prevent any coarse particles from escaping into thereceiving-chamber at the top of the shaft, I provide a deflector a abovethe top of the shaft. This deflector breaks the upward force of theair-currents,

and the coarse particles, instead of falling outside into the bin, aredeflected and brought back into the line of the shaft and thence to thepulverizer. The bottom of the shaft A may be closed, as shown at E inFig. 3, and the pulverized material and air forced into or through thepipe (1', and the air-currents, as before, will carry up the fineparticles. The bottom is provided with a door to permit the withdrawalof such material as may have accumulated.

Instead of air in the shaft, I may in some instances and for certainpigments use a column of water in the shaft A, the same action takingplace as with airthe coarse particles falling and the finer beingcarried up and held in suspension. The chamber in this instance willpreferably be divided and have overflows, so that the suspended materialcan settle for withdrawal.

It is evident that the foregoing methods are ones of rapidity andeconomy and have been found to be a practical way of overcoming theobjections referred to.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

In a pigment-separator, the combination, with the pulverizer andfan-blower, of a shaft above the exit-shaft of the pulverizer, saidshaft having openings for the admission of air above thepulverizer-shaft, a continuous funnel surrounding same and brought to apoint at one side thereof, a receiving-chamber, and a deflector securedto the top of said chamber and having a surface, which reflects thecoarser material into the shaft, located above the shaft A, as and forthe purpose set forth.

In testimony whereof I aflix my signature in presence of two Witnesses.

EDWVIN F. WARD. \Vitnesses:

WILLIAM MoLLoY, I. H. MACDONALD.

